Nuclear energy is the most compact form of energy known. Efficient methods of using nuclear energy to pump lasers are continuously being sought, but no one method proposed to date has been accepted as desirable or feasible. One feature a nuclear laser must have is a critical reactor assembly used in a manner other than a neutron source only, otherwise its potential is wasted. A reactor assembly, however, generates heat. This heat can degrade, even terminate laser output. Concepts using nuclear reactors generally envision the reactor operated in a pulsed mode, or the laser gas flowing and passing through coolant loops, to avoid the problem of reactor heat.
Metal excimers require heat to produce a vapor state in the metals. Output in many of the excimers has been limited in power in part due to the low atom densities achievable with the oven temperatures used to heat the metal (.about.1000.degree. K.) Nuclear reactors can be designed which generate temperatures much higher than conventional r-f or induction heated ovens, without requiring electrical input.
The Nuclear Energy Propulsion (NEP) vehicle utilizing Thermionic Energy (TEC) is such a reactor design. Such systems are disclosed by Eugene V. Pawlik and Wayne M. Phillips, "A Nuclear Electric Propulsion Vehicle for Planetary Exploration", J. Spacecraft Vol. 14, No. 9, pgs 518-525. The fuel in such systems is cooled by heat pipes, which operate at temperatures of 1650.degree. K.
Applicant's invention utilizes such a reactor in conjunction with thermionic converters which use the temperature to generate a DC voltage. The voltage is discharged in the heat pipes to vaporize metal lasants therein.
Such nuclear reactors could be changed to incorporate the principle of direct nuclear pumping (DNP). Fission coatings may be added to the inside of the heat pipes, or all of the fuel may be replaced with fission coatings. Then, in addition to an electric discharge, fission fragments are used to excite and ionize the metal vapors. Excitation and ionization by fission fragments increases the electrical efficiency of the metal vapor lasers.
Metal excimer lasers, such as HgCl* or HgCd*, are efficient lasers which radiate in the visible wavelengths. The use of nucelar reactors to provide an electric discharge and to vaporize the metals can demonstrate high total efficiency. High power lasers for laser isotope separation, inertial fusion, space based power plants, communications or beam weapons can be fielded which operate for many years unattended.